IDNLearn.com: Your trusted platform for finding reliable answers. Our community provides timely and precise responses to help you understand and solve any issue you face.

Select the correct answer.

Which equation models the same quadratic relationship as function [tex]\( f(x) = x^2 + 12x + 4 \)[/tex]?

A. [tex]\( y = (x + 6)^2 + 40 \)[/tex]

B. [tex]\( y = (x + 6)^2 - 32 \)[/tex]

C. [tex]\( y = (x \cdot 6)^2 - 32 \)[/tex]

D. [tex]\( y = (x - 6)^2 + 40 \)[/tex]


Sagot :

To determine which equation models the same quadratic relationship as the given function [tex]\( f(x) = x^2 + 12x + 4 \)[/tex], we need to check if the given function can be rewritten in the form of the options presented. Let's start by rewriting [tex]\( f(x) \)[/tex] in a form that resembles the given choices.

1. Complete the square for [tex]\( f(x) = x^2 + 12x + 4 \)[/tex]:

The standard form of completing the square for a quadratic function [tex]\( ax^2 + bx + c \)[/tex] involves creating an expression that represents a perfect square trinomial. Here's the process:

[tex]\[ f(x) = x^2 + 12x + 4 \][/tex]

First, take the coefficient of [tex]\( x \)[/tex], which is 12, and divide it by 2:

[tex]\[ \frac{12}{2} = 6 \][/tex]

Next, square this result:

[tex]\[ 6^2 = 36 \][/tex]

Add and subtract this square inside the function:

[tex]\[ f(x) = x^2 + 12x + 36 - 36 + 4 \][/tex]

Group the perfect square trinomial and simplify the constant term:

[tex]\[ f(x) = (x + 6)^2 - 36 + 4 \][/tex]

Simplify the constants:

[tex]\[ f(x) = (x + 6)^2 - 32 \][/tex]

2. Compare with the given options:

We can see that the equivalent form of [tex]\( x^2 + 12x + 4 \)[/tex] after completing the square is:

[tex]\[ f(x) = (x + 6)^2 - 32 \][/tex]

Now, we'll match this with the given options:

- Option A: [tex]\( y = (x + 6)^2 + 40 \)[/tex]

This is incorrect because it has +40 instead of -32.

- Option B: [tex]\( y = (x + 6)^2 - 32 \)[/tex]

This is correct because it matches our derived form exactly.

- Option C: [tex]\( y = (x \cdot 6)^2 - 32 \)[/tex]

This is incorrect because it involves [tex]\( x \cdot 6 \)[/tex] instead of [tex]\( x + 6 \)[/tex].

- Option D: [tex]\( y = (x - 6)^2 + 40 \)[/tex]

This is incorrect because it involves [tex]\( x - 6 \)[/tex] instead of [tex]\( x + 6 \)[/tex], and +40 instead of -32.

Therefore, the correct answer is:

[tex]\[ \boxed{B} \][/tex]